Automatic well flow valve



July 2l, 1953 J. D. NlxoN AUTOMATIC WELL FLOW VALVE Filed Nov. 8, 1948 5 Sheets-Shree*v 2 JNVENTOR. y D /V /xo/V J-DD JMW@

July 2l, 1953 J; D. NlxoN 2,646,062

AUTOMATIC WELL FLOW VALVE Filed Nov. 8, 1948 5 Sheets-Sheet. 5

JN VEN TOR. JEDDYD/V/xo/v tion,

Patented July 21, 1953 AUTOMATIC WELL FLOW VALVE Y J eddy D. Nixon, New Braunfels, Tex., assigner of one-half to Wilson Supply Company, Houston, Tex., a corporation of Texas Application November 8, 1948, seria1N6.5s,995

This invention relates to new and useful improvements in automatic well flow valves.

One object ofthe invention is to provide animproved automatic flow valve, adapted to be mounted on the outside of an eduction tubing for supplying pressure iiuid from the outer casing.

Another object of the invention is to provide an improved automatic flow valve employing a movable weight member for opening and closing the valve, whereby the weight provides the pressure differential between the pressure fluid and the hydrostatic pressure of the liquid in the tubing, necessary to operate the valve.

A further object of the invention is to provide an improved automatic valve wherein the flow passages are relatively large so as to provide free flowing which substantially eliminates sanding up and cutting; and also whereby a low pressure differential operates the Valve and large volumes of pressure iluid are supplied under high velocity with little or no seat cutting.

Still another object of the invention is to provide an improved automatic flow valveoi the type described employing an elastic valve seating member which not only provides cushioned closing but withstands severe poundingand will not leak. v

A construction designed to carry out the invention will be hereinafter described together with other features of the invention.

The invention will be more readily understood from a reading of the following specication and by reference to the accompanying drawing, wherein an example of the invention is shown, and wherein: i

Fig. 1 is an elevation of an automatic valve constructed in accordance with the invention mounted on an eduction tubing in an outer casing,

Fig. 2 is an enlarged view of the upper half portion of a string of tubing and casing having the upper portion of one of the valves mounted therein, a portion of the sub and the upper portion of said valve being illustrated in section with the valve closed, l

Fig. 3 is a vertical sectional view of the lower portion of the sub and valve,

Fig. 4 is a vertical sectional view of the upper portion of the valve assembly in its closed posi- Fig. 5 is a similar view of the upper portion Vof the valve assembly in its open position,

Figs. 6 and 'l are horizontal cross-sectionalY views taken on their respective lines of Fig. 2, and Fig. 8 is a similar view taken'onthe line 8 8 9 claims. (01.' 137-155) z e In the drawings the numeral I0 designates a short length of tubing or sub which is preferably of the upset collar type and is formed with pins II at each end having annular beveled shoulders I2 at their bases. The pins receive the usual coupling collars I3, whereby the sub may be connected in a string of well tubing. An upper hanger I4 is mounted on the side of the sub adjacent the upper shoulder I2, while a lower hanger I5 is mounted under the upper hanger adjacent the lower shoulder. These hangers may be welded in the sub.

The upper hanger I4 has a vertical bore I6 open at the bottom of said hanger and closed at its top. A lateral duct-I1 leads from the upper end of the bore to a port I8 in the sidewall of the sub. A bushing I9 is countersunk in an annular recess or socket 20, surrounding the bore I5. The bushing is sealed off from the bore by a gasket 2| and has a tubular shank 2-2 iitting snugly in said bore. The upper end of the shank terminates below the duct I1 and is formed with an annular valve seat23 which receives a check valve ball 24. A cylindrical, perforated cage or sleeve extends between the upper and lower hangers I4 and I 5, the upper end of the cage tting snugly around a dependent boss 26 on the bottomv of the bushing and being removably inserted in the counterbore 20.

A tubular pedestal 21 carries external sore threads 28 and is received in a vertical screw-V threaded bore 29 extending through the lower hanger I5. The pedestal is fastened in place by a set screw 3U. A head 3l is formed on the upper end of the pedestal and has an upstanding annular boss 32 which telescopes the lower end of the cage 25, whereby the latter is seated on the pedestal. It will be seen that by loosening the set screw 3B, the pedestal, by unscrewing, may be lowered sufficiently to withdraw the upper end of the cage from the socket 20 of the upper hanger, whereby the cage may be lifted off of the head 3I, when it is desired to gain access to parts in the cage or for any other purpose.

An elongate, cylindrical weight bar 33 is movable vertically in the cage, being of less diameter and spaced from the inner wall of said cage. The bar has a depending guide stem 34 engaging in the bore 35 of the pedestal.y At its upper end, the bar has a socket 36 receiving the depending klug 3l of a valve head 33 which is pivoted therein on a transverse pin 39. The valve head has a screw-threaded axial bore 40 receiving the lower screw-threaded end of a valve stem 4I, fastened therein by a set screw 42. An elastic valve collar 43, formed of soft plastic or other elastic material, is countersunk in the top of the head 38 withinl the upper end of the cage 25. The upper side of the collar has an inclined annular yface 44 adapted to engage a complementary seat l5 at the lower end of the bore 46 of the bushing i9, thereby sealing off said bore and shutting olf ilow of luid through said bore to the bore IB, duct Il and port I8. The bores 46 and I8, the duct I1, and port I8, form a ilow passage between the sub l and the cage 25.

An annular flow restricting member 4l is formed around the medial portion of the stem 4l so as to have a free sliding llt in the lower end of the bore 6, when the collar 43 is seated. The member 4l has an inclined, annular shoulder 4.3 at its top. A pair of spaced flanges or collars lll surround the upper end portion of the valve stem, one of said flanges 'being flush with the upper end of said stem and thus providing a flat surface for receiving the check ball 24 and holding it out of its seat 23, when the valve is closed. These flanges are slightly less in diameter than the bore 46 of the bushing so as to provide a restricted flow space therearound.

It will be noted (Figs. 3 and 4) that when the weight bar 33 is seated on the pedestal head 3l, the valve collar 43 will be unseated and the member 4'( will be withdrawn from the bore et. However, the flanges 49 will remain in said bore, thus restricting the flow of pressure fluid from the cage 25 to the port i3. The pedestal head 3l has a plurality of vertical ducts 5l? so that the pressure fluid may ow therethrough. When the weight bar 33 is elevated and the collar i3 cf its valve head 38 is seated, t -e bottom of said bar will offer a greater cross sectional area to the pressure fluid and the bar will thus be held in its elevated position.

The sub Il) is connected in a ystring of oil eduction tubing 5l which is mounted in a string of casing 52 in accordance with common oil-field practice, as is shown in Fig. 1. The automatic valve, indicated gene-rally by the numeral 53 in Fig. 1 is disposed in the casing which is filled with a suitable pressure fluid, such as gas under a working pressure of 400 to 500 pounds per square inch. When the valve is closed, as shown in Figs. 2 and 4, the check valve 24 is unseated, but the flow passage to the port I8 is shut off because the valve collar 43 is seated and thus pressure fluid cannot enter the tubing. When the valve is opened, as shown in Fig. 5, and gas is not flowing through the valve passage to the port Ill, the valve ball 24 will be seated and thus liquid or oil cannot flow from the tubing through said port into the casing.

The weight of the bar 33 constitutes a differential equivalent to a pressure differential between the pressure of the gas in the casing and the hydrostatic pressure of the liquid in the tubing above the port I8. As an illustration, if the gas in the casing is exerting a pressure of 460 pounds per square inch against the bottom of the bar 33, said bar may weigh substantially 19 lbs. and thus the valve will remain closed until the hydrostatic pressure in the tubing above the port I8, reaches substantially 440 pounds per square inch, whereupon the weight bar `will fall, thus unseating the valve collar 43 and withdrawing the pilot valve 41 from the bore 45.

The instant the pilot valve body 4l leaves the lower end of the bore 46, the ilow annulus lwill be increased because of the inclined shoulder 48 and this will cause the valve to open with a snap action. When the valve is opened to flow position as is shown in Fig. 5, the pressure fluid will bypass the flanges 49, unseat the ball 2f? and flow into the sub I0 and tubing 5I, by way oi the port IS. This flow will continue until th-e slug ci cil is elevated in the tubing in the usual way.

It will be be observed that the flow past the flanges 49 will be restricted and its velocity thus increased. This velocity will pick up as the slug of oil is elevated in the tubing because the load will be lightened. The stem il and the flanges 49 act as pistons and when the back pressure acting downwardly on this piston decreases to a predetermined point, the pressure uid will pick up the piston and close the valve. Where the opening pressure differential is substantially pounds per square inch, the closing pressure differential will be approximately pounds per square inch. This difference in pressure dinerentials is due to the energy required to lift the weight bar.

When the weight bar is lifted, the inclined shoulder gradually decreases the flow space as it enters the bottom of the bore 45, until the point is reached Where the valve is closed with a snap action. It is believed the operation of the valve under starting or kickoff conditions will be understood without further explanation. Like all automatic valves, this valve will remain closed unitil the liquid in the tubing rises sulllciently to build up the required hydrostatic pressure to open it.

The valve herein set forth has many advantages. It is pointed out that all flow openings such as I8, ll, i6 and 46 are large, particularly when compared to the small or pin-point openings found in the usual automatic valve. While the annular flow space around the ilanges /l is restricted it is ample to prevent clogging or sanding up and the consequent cutting.

As a rule, the flow passages of automatic valves are so small that it is necessar;7 to have these valves open at relatively high pressure differentials of from to 200 pounds per square inch in order to flow into the tubing enough cubic feet of gas under enough pressure to elevate the slug of oil. In the valve herein set forth, the inlet ow passages being large and the valve opening on a low diierential, large volumes of gas or pressure fluid under high velocity are admitted. This greatly reduces seat cutting and the volume of gas admitted to the tubing is depended upon rather than the high pressure of such gas.

By use of the elastic collar 43, which is preferably made of a medium hard plastic, such as Micarta, a cushion seating is had and the valve, when closed, will not leak and will stand considerable pounding. While the collar is relatively soft, it is not soft enough to permit grains of sand to embed therein.

The valve which has Ibeen described herein, is known as a tubing type, because the oil or liquid is elevated in the tubing and the pressure lluid is exteriorly supplied, and is to be distinguished from casing type valves wherein the pressure fluid is supplied from the tubing and the liquid elevated in the casing. This application is in some respects related to my copending application, Serial No. 58,996, filed of even date herewith.

The foregoing description of the invention is explanatory thereof and various changes in the size, shape and materials, as well as in the details of the illustrated construction may be made, within the scope of the appended claims, without departing from the spirit of the invention. n n

What claim and desire to secure by Letters Patent is: 1

1. An automatic well ow valve including, an upper support adapted to be mounted on a tubular conductor having a port, a lower support adapted to be mounted on a tubular conductor, the upper support having a valve seat and a flow passage from said seat adapted to be connected to the conductor port, a pedestal carried by the lower supporta perforated cage mounted on the pedestal engaging the upper support, a movable weight bar in'said pedestal, and a valve on the upper end of the bar adapted to engage the seat. Y

2. An automatic Avalve as set forth in claim 1, and a stem extending from the valve into the passage of the upper support, and 110Wv restricting means on the stem in said passage.

3. An automatic valve as set forth in claim 2, and a flow restrictor on the stem adapted vto enter the passage through the seat.

4; An automatic well flow valve including, a support adapted to be mounted on a .tubular conductor having a port, a passage in said support adapted to be connected to said port, a bushing mounted in said support having a bore connected with the passage at its upper end, a

and flow restricting flanges on said stem in saidv bushing bore. y 5. An automatic valve as set forth in claim 4, wherein the bushing has a valve seat at the upper end of its bore, and a check valve in the support passage adapted to engage said last named seat.

6. An automatic 110W valve including, a support adapted to be mounted on a tubular conductor having a port, said support having aV right angular flow passage therethrough adapted to be connected with said conductor port at its upper outer end, a bushing inserted in the flow passage having a. valve seat at its bottom, a Weight bar, a valve means at one end of the weight bar having a member slidable in the bushing, and flow restricting means carried on the member in the bushing for raising the bar to seat the valve means.

7. An automatic well flow valve as set forth in claim 6, wherein the bushing has anadditional valve seat at its upper end, and a check valve in the flow passage disposed to engage said seat for shutting off a reverse flow through said passage.

8. An automatic well flow valve as set forth in claim 6, with a support below the lower end of the weight bar, and a removable foraminous cage carried by the last named support and loosely surrounding the weight bar.

9.'An automatic well flow valve as set forth in claim 6, wherein the valve means includes an elastic collar for engaging the valve seat.

JEDDY D. NIXON.

References Cited in the flle of this patent 

